Malicious PDF — malware analysis report

Static analysis result for SHA-256 db33de8725103555…

MALICIOUS

PDF

71.4 KB Created: 2021-09-24 23:03:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8e56bcbc443167cec66af65629e5cbfa SHA-1: d0d8bf8d9868c354d8fe54bc2c8650a3ce39465f SHA-256: db33de87251035556b37d5784d3293ffe53f8b6a40b1ad082abd1bfb81fc2e9a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file containing embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities. The ML classifier and ClamAV detection strongly indicate maliciousness. The embedded JavaScript likely redirects the user to one of the numerous external URLs found, which are hosted on compromised or disposable domains, suggesting a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://philabc.ru/uplcv?utm_term=ditty+app+apk PDF link annotation
    • http://jump360.co/upload/files/20210913211829.pdfIn PDF document text
    • https://emtracing.net/userfiles/file/19536393545.pdfIn PDF document text
    • https://armour-technoz-ca.otzol.net/ckfinder/userfiles/files/95526708065.pdfIn PDF document text
    • http://www.leads-bd.org/app/webroot/js/ckfinder/userfiles/files/44114594244.pdfIn PDF document text
    • http://sobateracota.ro/mm/file/majuputubexunuvupi.pdfIn PDF document text
    • http://alhambra.kopanramen.com/uploads/files/56077926933.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/9950a19d1101ba8472d876bc1853b227/wowobaxebiwuribi.pdfIn PDF document text
    • http://teplolux72.ru/upload/file/16595263418.pdfIn PDF document text
    • http://shbaicun.com/userfiles/file/2021091220100673499.pdfIn PDF document text
    • http://nowator-zpu.pl/userfiles/file/tuxuwuz.pdfIn PDF document text
    • http://lachina.cn/upload/file/53529420750.pdfIn PDF document text
    • http://e-sheremet.com/img/jolesilero.pdfIn PDF document text
    • http://tythb.cn/uploadfile/files/52436281108.pdfIn PDF document text
    • http://www.leasebridge.com/CKUPimg/files/kovukubuwulobadejepe.pdfIn PDF document text
    • https://cemb.ca/upload/editor/file/91708827361.pdfIn PDF document text
    • http://gocreate.termall.pl/upload/fck/file/98692061801.pdfIn PDF document text
    • http://daegyung.kr/userfiles/file/20210903050517.pdfIn PDF document text
    • https://marblobath.com/app/webroot/img/files/35309100487.pdfIn PDF document text
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/ad04ff3fc25cff280549b3ebc4a395ac/33423064371.pdfIn PDF document text
    • http://n-production.com/upload/fckeditor/file/wivuse.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/161355a17775bd---tosefoduz.pdfIn PDF document text
    • http://mustang.tom.ru/jsplugins/ckfinder/userfiles/files/64259163714.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b3df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3DF 9780 bytes
SHA-256: 5e31c9d225f00e2c1d5cf6878796fd965cd6d6c2a9ded02e11201496b35a678b
font_01_sfnt_off0000c970.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC970 18064 bytes
SHA-256: 213a2e9bf992318bc8177907abf183dd51acff495f4d3c420715d9512b9aac4d
font_02_sfnt_off0000f7ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1